1. Field
Apparatuses and methods consistent with exemplary embodiments relate to signal transmission and processing, and more specifically, to non-binary encoding and signal processing.
2. Description of the Related Art
In a next generation communication system which requires a high capacity data transmission, a quadrature-amplitude modulation (QAM) is used as a modulation method which allows high frequency efficiency.
Compared with a binary low density parity check (LDPC) code, the higher is a modulation order of a QAM modulation method which is used in a communication system for a non-binary LDPC code defined over a Galois Field (GF), the more performance gain does the non-binary LDPC have and the more robust is the non-binary LDPC against an error floor. However, while a modulation order of a QAM modulation method increases, if the size of the GF, q, also increases, complexity of a non-binary LDPC code may increase drastically. Therefore, the size of the GF of a non-binary LDPC code, q, and a modulation order of a QAM modulation method should be adequately selected in consideration of the complexity of encoding.
Different variable nodes have different error correction capabilities depending on a modulation order in the iterative decoding process of a non-binary LDPC code. Accordingly, considering that decoding performances may differ depending on a method of combining codeword symbols into a single transmission symbol, better ways to mapping codeword symbols to a transmission symbol need to be sought for the purpose of achieving improved decoding performances.